Containment sumps are typically found at fuel service stations whereby they are installed below the surface to provide a means of access to the underground piping connections, submersible pumps, leak detection sensors, fire extinguisher and other plumbing components usually found connected to the top of underground storage tanks or under fuel dispensing units. There are generally two types of containment sumps which are similar in purpose but different in design. The first type, is commonly referred to as a "tank sump" which is installed and connected to the top of an underground storage tank. The second type is commonly referred to as a "dispenser sump", which is installed under a fuel dispensing unit.
Containment sumps are multi-purpose in function: 1. They provide a means of surface access to equipment, plumbing and miscellaneous devices, installed underground. 2. They provide a means of ground isolation for contained components to prevent corrosion and decay. 3. They provide a means of secondary containment for those contained components which handle hazardous liquids. 4. They perform as a collection sump for double wall piping entering the sump. Each of these functions will be illustrated and described in detail in this document.
In recent years there has been a national mandate to protect our ground water from hazardous liquid contamination. As a result, there has been federal, state and local legislation created throughout the country requiring stringent regulations on the manner in which hazardous liquids are stored and piped in underground applications. These new regulations require the replacement of leaking underground storage units, storage tanks and associated underground piping. These regulations have also established new design criteria to prevent future tanks and piping from leaking into the environment.